This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.

What is it?

Under normal conditions, Naphthalene is a white to light brown solid which has a strong, characteristic smell. It evaporates easily and is flammable. It is sensitive to moisture and sunlight. Naphthalene does not dissolve in water, but dissolves well in most organic (carbon-containing) solvents.

What is it used for?

The most common use of Naphthalene is in moth repellants, such as mothballs. It is also used to make dyes, leather tanning agents, resins, lubricants, antiseptics, toilet deodorants and other insecticides.

Where does it come from?

Releases of Naphthalene may occur during its manufacture or use in the chemical industry - and when products such as mothballs and toilet deodorants are used and disposed of. Naphthalene is found naturally in fossil fuels and is formed when they are burned. The most significant releases of Naphthalene will occur from industry burning fossil fuels. Spills to land and water bodies can also occur when fossil fuels such as coal tar and fuel oil are transported, stored and disposed of.

How might it affect the environment?

High level exposure to Naphthalene is toxic to wildlife, particularly aquatic organisms. However, it breaks down quickly in the environment and so only very large releases (resulting from an accidental spill for example) are likely to cause harm. In the air, it is broken down by moisture and sunlight within a matter of days. Naphthalene binds weakly to soils and so easily seeps into water bodies, where it is broken down by bacteria. Naphthalene does not accumulate in wildlife, but it can be passed from mother animals to their young. It is not considered likely that Naphthalene has any effects on the global environment.

How might exposure to it affect human health?

Naphthalene can enter the body either by the inhalation of air containing naphthalene, accidental ingestion of naphthalene, or by dermal contact with naphthalene and products containing naphthalene. Inhalation of air containing elevated levels of naphthalene can lead to a range of adverse health effects including headache, nausea, confusion, convulsions and in extreme cases coma. Exposure to high levels of naphthalene can also cause haemolytic anemia (blood disorder), with symptoms including fatigue, lack of appetite, paleness of the skin and restlesness. Exposure for long periods of time can affect the peripheral nervous system, kidneys and the liver. Ingestion of naphthalene can result in abdominal pain, nausea vomiting, diarrhoea, fever, blood in the urine, haemolytic anaemia, jaundice and in extreme cases convulsions and coma. Dermal contact with naphthalene can skin irritation and dermatitis. Contact with the eyes can cause irritation and can damage the cornea. Exposure for long periods of time can lead to the development of cataracts. The International Agency for Research on Cancer has designated naphthalene as a possible carcinogen. However, exposure to naphthalene at normal background levels is unlikely to have any adverse effect on human health.

What steps are being taken to limit the potential impacts?

Releases of Naphthalene are controlled through the UK Pollution, Prevention and Control (PPC) Regulations, the Food and Environmental Protection Act (FEPA 1985), the Control of Pesticides Regulations (COPR 1986) and the UK Surface Waters (Dangerous Substances) Regulations (SI 1997/2560). Naphthalene is not listed as authorised for use in the UK in the Pesticide Safety Directorate. European Directives regulating levels of Naphthalene include that concerned with pollution of the aquatic environment (76/464/EEC) and it is listed as a "priority hazardous substance" under the Water Framework Directive. At an international level, Naphthalene is listed as a candidate substance for priority action under the Helsinki and OSPAR Conventions which protect the marine environments of the Baltic Sea and north-east Atlantic Ocean respectively.